Accelerated radiation: Some doctors want more evidence it works

For breast cancer patients who need radiation therapy, the option to reduce its duration from about seven weeks to five days can be appealing.

Accelerated radiation, in various forms, has been in use for nearly 10 years. While some physicians are confident that it's effective, others are holding out for more evidence.

The standard treatment after a lumpectomy is radiation of the entire breast, the thinking being that the radiation will attack any cancer cells that might have spread from the tumor. Dr. Andrew Salner, chief of the department of radiation oncology at Hartford Hospital, said advances in mammography have allowed physicians to catch tumors at earlier and smaller stages, and that led to the idea of treating just the area around a tumor.

By using concentrated and narrowly focused doses of radiation on just the area of the breast where the tumor is, the therapy lasts only five to seven days, compared to the four- to seven-week period of traditional whole breast radiation therapy. The most common form of accelerated radiation is brachytherapy, which uses catheters inserted in the breast to deliver radiation directly to the area of the tumor.

"If you're treating a smaller volume, you cando it in a shorter time period," Salner said. "It's more convenient for women who were dragged through surgery and possibly chemotherapy and would rather not be schlepping back for seven weeks."

Salner said Hartford Hospital has offered accelerated radiation for several years, and about 15 percent of patients with breast cancer qualify as candidates for it. While many women with breast cancer prefer to stick with the "tried and true" standard regimen of radiation, Salner said he believes the majority of women who qualify do opt for the shorter course.

Based on his experience at Hartford Hospital and what he has seen in studies, he's confident that the five days of radiation are as successful as the seven-week regimen at reducing the risk of recurrence.

Dr. Kimberly Caprio, breast surgeon at St. Francis Hospital and Medical Center, said the hospital offers accelerated radiation on a very limited basis. About 10 patients a year receive it. Patients who qualify for it tend to be older, she said, and have tumors that are small and located away from the skin. If the tumor is too shallowly located, she said, the treatment can damage the skin.

Dr. Suzanne B. Evans, an assistant professor at Yale University School of Medicine and director of radiation oncology at Lawrence and Memorial Hospital in New London, said an advantage of accelerated radiation is that it causes less discomfort. Adverse effects of conventional radiation therapy are usually related to the skin, she said, and partial breast radiation minimizes those effects.

"What women find most troublesome about whole breast radiation is that the breast gets red, the skin will peel, especially in the tail of the breast, close to the armpit," she said. "That peeling can be very uncomfortable. We don't see that at all with the partial breast."

Overall, Evans said, "the results have been very good. ... The partial breast radiation is extremely well tolerated by the women."

Research Still Underway

Exactly how good it is, though, is still being determined. Studies have shown that there's a 3 percent to 5 percent risk of recurrence over five years with whole breast radiation, Evans said. Some studies suggest that accelerated partial breast irradiation has a similar success rate, but there aren't yet any long-term data from randomized trials, said Heather Taffett Gold, an an assistant director of health disparities and outcomes research at the New York University Cancer Institute.

"There's 20 years of evidence with mastectomy vs. lumpectomy with whole breast radiation," she said. "So some physicians would like to see a longer outcome [for partial breast radiation]."

Dr. Kristen Zarfos, surgeon and medical director of the Comprehensive Breast Health Center at St. Francis Hospital and Medical Center, said she wants more evidence of its success before she'll recommend accelerated radiation.

"For me, it comes down to this: I don't want to offer to a patient a treatment that I am not certain meets the gold standard of treatment," she said.

The National Surgical Adjuvant Breast and Bowel Project has led a national study of more than 4,000 women, including 59 recruited by Yale-New Haven Hospital, designed to get long-term results on partial breast radiation. That trial closed in April and long-term results will be available in about five years.

Evans is optimistic that partial breast radiation will prove as effective as more conventional methods, but until there's more robust evidence, she said Yale-New Haven is offering it only in clinical trials.

"In some institutions, they do it off-trial," she said. "We don't agree to that because it hasn't been proven to be equivalent to the standard of care. We're really still learning a lot about this technique."

For women who enroll in clinical trials, she said, between 60 percent and 70 percent of women who qualify go with the accelerated treatment.

"Some women will say, 'I understand that you guys are still learning about this, that's it's not yet the standard of care. I'm not a pioneer. I don't want to do it,'" Evans said. "Other women will say, 'So there have been hundreds of other women treated in this fashion and the risks of recurrence are between 3 and 5 percent. I'm comfortable with that.'"